City Utilities' wind and solar power research projects, in conjunction with the Missouri Department of Natural Resources, provide research and educational opportunities in Springfield, including renewable energy output data for wind and renewable energy output data for solar.
How It Works
The energy produced from the wind turbine and the solar arrays is passed through an inverter to synchronize it to CU's existing power supply. From there the energy passes through a meter so it can be measured, and is connected directly into the breaker panel serving the electrical requirements of the TecHOUSE. This renewable energy production satisfies only a small portion of the electricity needed for the operation of the building.
Consumers considering the installation of supplemental electric generation, including renewable energy, must contact their local utility provider. For safety reasons, measures need to be in place to insure power generated through alternative means does not feed back into the local utility grid.
Output Projections
The anticipated annual energy output for the wind turbine is 17,500 kilowatt-hours (kWh) and 7,700 kWh for the solar panels, for a combined total of 25,200 kWh. This means the wind turbine and solar arrays are expected to produce electricity 20 percent of the time. The units demonstrated were sized for commercial application at a total cost of $130,000. Units installed for home use would be sized and priced accordingly. Based upon the expected output for both the wind turbine and solar arrays, homeowners can expect a lengthy payback period on projected energy savings for a residential application.
Wind Turbine
Our wind turbine is placed atop a 90-feet tower. Each blade is 11.5 feet in length with a rotor diameter of 23 feet. A 7.5 mph wind speed is needed for start-up. Generation begins at 8 mph. The wind turbine needs constant wind above 8 mph to cause rotation of the blades, which in turn spins a shaft connected to a generator, which makes electricity. An external anemometer measures the wind speed and transmits this data to the controller. At 31 mph wind speed the turbine has reached full load and is capable of producing 10 kilowatts. To avoid damaging the turbine, a safety controller automatically tapers the turbine down when wind speeds reach 36 mph.
Solar Panels
Two, 13 feet x 15 feet racks hold the photovoltaic solar panel arrays. One array is stationary and the second dynamically tracks the sun; meaning it moves to absorb the maximum amount of solar energy throughout the day. The size of the arrays and the weather determine the amount of electricity produced.
